1. Field of the invention
This invention relates to a micro-displacement measuring apparatus which can attain accurate and ready measurement of micro-amounts and the direction of displacement of objects.
2. Description of the prior art
As measuring methods for measuring the amount of displacement of an object to be measured, there have been (1) a method using dial gauges; (2) a method using optical levers; (3) a method using variation of the capacity of condensers; (4) a method using differential transformers; and (5) a method using optical interference, etc. However, methods (1) and (2) are disadvantageous in that the micro-displacement of the object cannot be measured. Methods (1), (3) and (4) are also disadvantageous in that measuring probes must be connected to the object. Method (3) is also inferior in that a linear relationship cannot be attained between the variation of the capacity of the condensers and the micro-displacement of the object. Method (5) is inferior in that since the movement of the interference pattern must be observed to detect the direction of displacement of the object, the direction thereof cannot be readily detected.